Moon, Mercury and Regulus

Another busy day. When I arrived home, Christina told me about The Moon at the Rear Window and more two stars. Indeed the one to the left is Mercury, the nearest planet to the Sun. It is curious because temperatures vary a lot there: the side that faces the Sun has extremely high temperatures, while the other side has extremely low temperatures. The other is Regulus, the main star of constellation Leo, the Lion. This star is around 77 light-years from here, or around 728,481,600,000,000 km, SO far...